One-Page Checkout [Support Thread]

[lat9]

perhaps not that odd. from

https://www.php.net/manual/en/function.empty.php

Note:

Prior to PHP 5.5, empty() only supports variables; anything else will result in a parse error. In other words, the following will not work: empty(trim($name)). Instead, use trim($name) == false.

Nice one, @carlwhat! I'm guessing that that statement applies to constant definitions, too, since they're not variables.